Preventive or remedy for glaucoma

ABSTRACT

There is provided a preventive for glaucoma or a preventive or a remedy for ocular hypertension, with a potent ocular hypotensive effect and prolonged duration thereof. A preventive or a remedy for glaucoma comprising a Rho kinase inhibitor and an α 1  blocker in combination.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims the benefits of priority to U.S. Ser. No. 11/993,101, filed Dec. 19, 2007, which is the national stage of PCT/JP06/312266, filed Jun. 20, 2006. The entire contents of these applications are incorporated herein by reference. The present application also claims the benefits of priority to Japanese Patent Application No. 2005-180535, filed Jun. 21, 2005.

TECHNICAL FIELD

The present invention relates to a preventive or a remedy for glaucoma or ocular hypertension.

BACKGROUND ART

Glaucoma is a disease characterized by the elevation of intraocular pressure (IOP) due to various pathogenesis leads to damage and atrophy of the optic nerve resulting in the abnormal visual field, and thus visual acuity is gradually reduced. Since the optic nerve does not recover once atrophy occurs, glaucoma is a refractory disease in that not only vision is lost if glaucoma is untreated, but also the condition is only maintained even after successful treatment, and recovery cannot be expected. Furthermore, ocular hypertension, which may lead to development of glaucoma over a long time although in the absence of visual field defects, also has a similar risk.

Glaucoma is classified into three types: congenital (developmental) glaucoma, secondary glaucoma, and primary glaucoma. Patients with congenital (developmental) glaucoma are born with growth deficiency of the iridocorneal angle, and obstruction of the aqueous outflow causes this type of glaucoma. Secondary glaucoma arises as a result of inflammation or injury and is caused by such as uveitis or ocular trauma as well as hemorrhage due to diabetes, long-term use of steroid hormones for the treatment of other diseases, and the like. Primary glaucoma is a generic name of glaucomas of types with unclear causes and occurs most commonly of glaucomas, with a high incidence among middle aged and elderly persons. Primary glaucoma and secondary glaucoma are further subdivided into two types, open-angle glaucoma and angle-closure glaucoma, depending on the blockage of the aqueous outflow. While many patients develop normal tension glaucoma in the absence of elevated IOP, the primary aim of glaucoma treatment is to lower the IOP.

For the treatment of glaucoma, laser treatment (laser trabeculoplasty), surgical therapy (trabeculectomy or trabeculotomy), or the like is performed when IOP cannot be controlled with a drug or a patient with angle-closure glaucoma has an acute glaucoma attack, but drug therapy is used as the first line therapy.

Drugs used in the drug therapy of glaucoma include sympathetic nerve stimulants (nonselective stimulants such as epinephrine and α₂ stimulants such as apraclonidine), sympathetic nerve blockers (β blockers such as timolol, befunolol, carteolol, nipradilol, betaxolol, levobunolol, and metipranolol and α₁ blockers such as bunazosin hydrochloride), parasympathetic nerve agonists (pilocarpine, etc.), carbonic anhydrase inhibitors (acetazolamide, etc.), prostaglandins (isopropyl unoprostone, latanoprost, travoprost, bimatoprost, etc.), and so forth.

Of these, bunazosin hydrochloride is a drug first developed as an agent for selectively blocking sympathetic nerve α₁ receptors, unlike existing remedies for glaucoma. As its mechanism of action, bunazosin hydrochloride locally acts on the eyes by instillation and lowers IOP by promoting aqueous outflow from the uveoscleral outflow pathway (Non-patent Document 1).

Meanwhile, Rho kinase inhibitors have been found as candidate remedies for glaucoma based on a novel mechanism of action (Patent Documents 1 and 2). Rho kinase inhibitors lower IOP by promoting aqueous outflow from the trabecular outflow pathway (Non-patent Document 2), and it is further suggested that this action may be attributed to changes in the cytoskeleton of a trabecular meshwork cells (Non-patent Documents 2 and 3).

In the treatment of glaucoma and ocular hypertension, drugs having an ocular hypotensive action are used in combination to enhance the additive ocular hypotensive effects. For example, combination use of a prostaglandin and a sympathetic nerve blocker (Patent Document 3), or a combination of some drugs having an ocular hypotensive action (Patent Document 4), and the like have been reported. Furthermore, combination use of a Rho kinase inhibitor and a β blocker (Patent Document 5) and a remedy for glaucoma comprising a Rho kinase inhibitor and a prostaglandin in combination (Patent Document 6) have also been reported.

However, the above-mentioned known remedies and therapies for glaucoma and ocular hypertension are far from satisfactory in view of the potency of the ocular hypotensive effect and the duration of action. In particular, it is more difficult to lower normal IOP in patients with normal tension glaucoma rather than lower elevated IOP. The above-mentioned existing drugs and combinations thereof have limitations in the treatment of normal tension glaucoma, and enhancement of the ocular hypotensive action is needed in the clinical setting.

Under such circumstances, there has been no report on glaucoma treatment using a Rho kinase inhibitor and a selective sympathetic nerve α₁ receptor blocking agent in combination, and there has been no description about the cooperative effect of such a combination.

[Patent Document 1] WO00/09162 [Patent Document 2] JP-A-11-349482 [Patent Document 3] Japanese Patent No. 2726672 [Patent Document 4] WO02/38158 [Patent Document 5] JP-A-2004-182723 [Patent Document 6] JP-A-2004-107335 [Non-patent Document 1] Journal of Japanese Ophthalmological Society, 94 (8), 762-768 (1990) [Non-patent Document 2] IOVS, 42 (1), 137-144 (2001) [Non-patent Document 3] IOVS, 42 (5), 1029-1037 (2001) DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a preventive or a remedy for glaucoma or ocular hypertension with a potent ocular hypotensive effect and a prolonged duration of action.

The inventors of the present invention conducted various researches in order to achieve the foregoing object. As a result, we have found that a potent ocular hypotensive effect is exerted by administering a Rho kinase inhibitor and an α₁ blocker in combination, and the duration of action is prolonged.

Specifically, the present invention relates to the followings.

1) A preventive or a remedy for glaucoma comprising a Rho kinase inhibitor and an α₁ blocker in combination. 2) A preventive or a remedy for ocular hypertension comprising a Rho kinase inhibitor and an α₁ blocker in combination. 3) Use of a Rho kinase inhibitor and an α₁ blocker in combination for production of a preventive or a remedy for glaucoma. 4) Use of a Rho kinase inhibitor and an α₁ blocker in combination for production of a preventive or a remedy for ocular hypertension. 5) A method for preventing or treating glaucoma, wherein the method comprises administrating a Rho kinase inhibitor and an α₁ blocker in combination. 6) A method for preventing or treating ocular hypertension, wherein the method comprises administrating a Rho kinase inhibitor and an α₁ blocker in combination.

According to the present invention, a preventive or a remedy for glaucoma or ocular hypertension with a potent ocular hypotensive effect and a prolonged duration of action can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing changes in IOP over time in each treatment group. IOP is shown as a change from the initial IOP (mean±standard error). ∘, bunazosin alone group; □, (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine alone group; Δ, bunazosin plus (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine group.

FIG. 2 is a graph showing changes in IOP over time in each treatment group. IOP is shown as a change from the initial IOP (mean±standard error). ∘, bunazosin alone group; □, hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine alone group; Δ, bunazosin plus hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine group.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, “Rho kinase inhibitor” refers to a substance that inhibits Rho kinase, an enzyme phosphorylating “Rho” known as one of low molecular weight GTP binding proteins.

Examples of such Rho kinase inhibitors include isoquinoline derivatives described in JP-A-11-349482 (the above-mentioned Patent Document 2), compounds described in WO05/37198, WO05/37197, WO05/35501, WO05/35506, WO05/35503, WO05/34866, WO04/84813, JP-A-2004-250410, WO04/39796, WO04/22541, WO03/59913, WO03/62227, WO01/68607, and WO01/56988, (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine (WO99/20620), hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine (Biochem. Biophys. Res. Commun. 262 (1), 211-215 (1999)), Y-39983 (BIO Clinica, 17[13], 1191-1194 [2002]; The 4th Int. Symp. Ocular Pharmacol. Pharm. [Feb. 28, 2002, Seville] 2002: 2; Annu. Meet. Assoc. Res. Vision Ophthalmol. [May 1, 2005, Fort Lauderdale] 2005: Abst. 3787/B145), and so forth.

Of these, (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine or salts thereof, hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine or salts thereof, and Y-39983 are more preferred, and salts of (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine are particularly preferred.

(S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine is a compound having antagonistic actions against substance P and leukotriene D4 in addition to a Rho kinase inhibiting action and can be produced by known methods such as, for example, the method described in WO99/20620.

Hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine can be produced by known methods such as, for example, the method described in JP-A-61-227581 and, further, can be purchased and used as a drug (Eril® S Injection [nonproprietary name: fasudil hydrochloride hydrate], Asahi Kasei Pharma).

Furthermore, Y-39983 is known to lower IOP in rabbits with normal IOP from 1 hour after instillation, shows the maximum ocular hypotensive effect at 2 to 4 hours after instillation, and has a potent action dependent on the concentration, with the maximum IOP reduction of 15 mmHg at a concentration of 0.10 (BIO Clinica, 17 [13], 1191-1194 [2002]; The 4th Int. Symp. Ocular Pharmacol. Pharm. [Feb. 28 2002, Seville] 2002: 2; Annu. Meet. Assoc. Res. Vision Ophthalmol. [May 1, 2005, Fort Lauderdale] 2005: Abst. 3787/B145).

Examples of salts of (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine and hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine include pharmaceutically acceptable salts such as salts of inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, and hydrobromic acid and salts of organic acids such as acetic acid, tartaric acid, lactic acid, citric acid, fumaric acid, maleic acid, succinic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, naphthalenesulfonic acid, and camphorsulfonic acid, and hydrochlorides are particularly preferred.

(S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine and hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine or salts thereof can exist not only as unsolvated forms, but also as hydrates or solvates, and the present invention includes all the crystalline forms of these compounds and hydrates or solvates thereof.

In the present invention, “α₁ blocker” refers to a drug that inhibits the sympathetic nervous system by binding to α₁ receptors of the sympathetic nerve to inhibit the binding of nerve transmitters.

Examples of such an α₁ blocker include bunazosin, indole derivatives described in WO99/043652, in particular, (R)-3-[7-carbamoyl-5-[2-[[2-(2-ethoxyphenoxy)ethyl]amino]propyl]-1H-indol-1-yl]propyl hydrochloride pivalate (KRG-3332 (Kissei Pharmaceutical Co., Ltd.)), and so forth. Of these, bunazosin is most preferred.

Bunazosin is a drug first developed as an agent for selectively blocking sympathetic nerve α₁ receptors and is known to have an ocular hypotensive effect by promoting aqueous outflow from the uveoscleral outflow pathway (J. Ocular Pharmacol. Ther. 14 [3]: 217 [1998]). Bunazosin can be produced by known methods such as, for example, the method described in JP-A-49-066690. Furthermore, “Detantol® 0.01% Ophthalmic Solution” (Santen Pharmaceutical Co., Ltd.), a remedy for glaucoma and ocular hypertension, can be used as a preparation for instillation.

When a Rho kinase inhibitor and an α₁ blocker are used in combination, a potent and prolonged ocular hypotensive effect is exhibited even from normal IOP as shown in the examples described later. Therefore, a medicament containing these compounds is useful as a preventive or a remedy for glaucoma or ocular hypertension. Here, examples of glaucomas include primary open-angle glaucoma, normal tension glaucoma, glaucoma with hypersecretory form, ocular hypertension, acute angle-closure glaucoma, chronic angle-closure glaucoma, plateau iris syndrome, combined-mechanism glaucoma, steroid glaucoma, pseudoexfoliation glaucoma, pigmentary glaucoma, amyloid glaucoma, neovascular glaucoma, malignant glaucoma, and so forth. Furthermore, ocular hypertension is also called “high blood pressure of the eye” and refers to a symptom with abnormally high IOP even in the absence of any clear lesion in the optic nerve. Many high IOP conditions such as postoperative high IOP fall within the scope of the present invention.

The preventive or the remedy for glaucoma or ocular hypertension comprising a Rho kinase inhibitor and an α₁ blocker in combination of the present invention may be prepared in one dosage form comprising effective amounts of the respective drugs at a suitable mixing ratio as a combination drug or a kit used by administering preparations each comprising an effective amount of drug either simultaneously or separately at an interval.

The above-described preparation is preferably used as an ophthalmological preparation, particularly preferably as a preparation for instillation, and such an ophthalmic preparation may be aqueous eye drop, nonaqueous eye drop, suspension eye drop, emulsion eye drop, eye ointment, and the like. Such a preparation can be produced by preparation methods known to those skilled in the art as a composition suitable for the dosage form by adding pharmacologically acceptable carriers such as, for example, tonicity agents, chelating agents, stabilizers, pH modifiers, preservatives, antioxidants, solubilizing agents, and thickening agents, if necessary.

Examples of tonicity agents include saccharides such as glucose, trehalose, lactose, fructose, mannitol, xylitol, and sorbitol, polyhydric alcohols such as glycerine, polyethylene glycol, and propylene glycol, inorganic salts such as sodium chloride, potassium chloride, and calcium chloride, and so forth, and the addition amount thereof is preferably 0 to 5% by weight based on the total amount of the composition.

Examples of chelating agents include edetates such as disodium edetate, calcium disodium edetate, trisodium edetate, tetrasodium edetate, and calcium edetate, ethylenediamine tetraacetate, nitrilotriacetic acid or salts thereof, sodium hexametaphosphate, citric acid, and so forth, and the addition amount thereof is preferably 0 to 0.2% by weight based on the total amount of the composition.

Examples of stabilizers include sodium hydrogen sulfite and so forth, and the blending quantity thereof is preferably 0 to 1% by weight based on the total amount of the composition.

Examples of pH modifiers include acids such as hydrochloric acid, carbonic acid, acetic acid, citric acid, phosphoric acid, and boric acid, further alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate or hydrogen carbonates, alkali metal acetates such as sodium acetate, alkali metal citrates such as sodium citrate, bases such as trometamol, and so forth, and the blending quantity thereof is preferably 0 to 20% by weight based on the total amount of the composition.

Examples of preservatives include sorbic acid, potassium sorbate, parahydroxybenzoate esters such as methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, and butyl parahydroxybenzoate, chlorhexidine gluconate, quaternary ammonium salts such as benzalkonium chloride, benzethonium chloride, and cetylpyridinium chloride, alkylpolyaminoethylglycine, chlorobutanol, Polyquad, polyhexamethylene biguanide, chlorhexidine, and so forth, and the blending quantity thereof is preferably 0 to 0.2% by weight based on the total amount of the composition.

Examples of antioxidants include sodium hydrogen sulfite, dry sodium sulfite, sodium pyrosulfite, concentrated mixed tocopherol, and so forth, and the blending quantity thereof is preferably 0 to 0.4% by weight based on the total amount of the composition.

Examples of solubilizing agents include sodium benzoate, glycerine, D-sorbitol, glucose, propylene glycol, hydroxypropylmethylcellulose, polyvinylpyrrolidone, macrogol, D-mannitol, and so forth, and the blending quantity thereof is preferably 0 to 3% by weight based on the total amount of the composition.

Examples of thickening agents include polyethylene glycol, methylcellulose, ethylcellulose, carmellose sodium, xanthan gum, sodium chondroitin sulfate, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, and so forth, and the blending quantity thereof is preferably 0 to 70% by weight based on the total amount of the composition.

An ophthalmic preparation can be prepared by, for example, dissolving or suspending desired ingredients of the above-mentioned compounds in an aqueous solvent such as sterilized purified water or physiological saline or a nonaqueous solvent such as vegetable oil such as cottonseed oil, soybean oil, sesame oil, or peanut oil at a predetermined osmotic pressure and subjecting the solution or suspension to sterilization such as sterilization by filtration. When an eye ointment is prepared, an ointment base can be added in addition to the above-mentioned various ingredients. The above-mentioned ointment base is not particularly limited, but preferred examples thereof include oily bases such as Vaseline, liquid paraffin, and polyethylene, emulsion bases obtained by emulsifying the oil phase and the aqueous phase with a surfactant or the like, water-soluble bases comprising hydroxypropylmethylcellulose, carboxymethylcellulose, polyethylene glycol or the like, and so forth.

When the preventive or the remedy for glaucoma or ocular hypertension of the present invention is provided as a kit, It can be designed so that drugs each comprising a Rho kinase inhibitor or an α₁ blocker prepared as described above should be separately packaged, and each drug preparation is removed from each package before use. Furthermore, both the drug preparations can be packaged in a form suitable for combination use for each dose.

When the preventive or the remedy for glaucoma or ocular hypertension of the present invention is administered, the dose varies depending on the patient's body weight, age, sex, symptom, dose form, number of dosages, and the like, but the usual adult daily dose is in the range of 0.025 to 2000 preferably 0.1 to 1000 μg of a Rho kinase inhibitor, and 10 to 1250 μg, preferably 50 to 250 μg of an α₁ blocker.

The number of dosage is not particularly limited, but it is preferable to administer the dose once daily or divide the dose into several times. One to several drops of a liquid eye drop can be instilled as one dose. When the preparations are packaged as a kit, the individual preparations may be administered simultaneously or at an interval of 5 minutes to 24 hours.

The present invention will be explained more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples.

EXAMPLES Example 1

To examine usefulness of combination use of a Rho kinase inhibitor and an α₁ blocker, the ocular hypotensive effects were compared by administering either of these drugs alone or both in combination to laboratory animals.

1. Preparation of Test Compound Solutions

A. Preparation of (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine solution

(S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine-hydrochloride dihydrate was dissolved in physiological saline, and the solution was neutralized (pH 6.0) by adding sodium dihydrogenphosphate and sodium hydroxide to prepare a (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine solution at a desired concentration.

B. Preparation of hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine solution

The commercially available “Eril® S Injection” (Asahi Kasei Pharma) was used as it was.

C. Preparation of Bunazosin Solution

The commercially available “Detantol 0.01% Ophthalmic Solution” (Santen Pharmaceutical Co., Ltd.) was used as it was.

2. Test Method

The ocular hypotensive effect was examined after the combination use of (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine and bunazosin. As a control, the ocular hypotensive effect was also examined after the use of bunazosin alone or (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine alone.

Similarly, the ocular hypotensive effect was examined after the combination use of hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine and bunazosin. As a control, the ocular hypotensive effect was also examined after the use of bunazosin alone or hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine alone.

A. Drugs and Animals Used in Test

(S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine solution: 0.5% solution (instillation volume, 50 μL) Hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine solution: fasudil hydrochloride hydrate injection (1.5% solution [trade name: Eril® S Injection]; instillation volume, 50 μL) Bunazosin Solution: bunazosin ophthalmic solution ([trade name: Detantol 0.01% Ophthalmic Solution]; instillation volume, 50 μL) Laboratory Animals: Japanese white rabbits (male JW rabbits, 5 to 10 animals per group)

B. Administration and Measurement (1) Administration of Drugs in Combination

-   1) One drop of 4% oxybuprocaine hydrochloride ophthalmic solution     (trade name: Benoxil Ophthalmic Solution 0.4%) was instilled in both     eyes of the laboratory animals for local anesthesia (only data for     the instilled eyes are shown). -   2) IOP was measured immediately before administration of the test     compound solution as the initial IOP. -   3) The bunazosin solution was instilled in one eye of the laboratory     animals, followed by the instillation of     (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine     solution in the same eye. -   4) At 1 hour, 2 hours, 3 hours, 4 hours, and 5 hours after the     instillation of both drugs, one drop each of 0.4% oxybuprocaine     hydrochloride ophthalmic solution was instilled in both eyes for     local anesthesia, and IOP was measured.

(2) Administration of Single Drug Alone

The (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine solution alone or the bunazosin solution alone was instilled, and then tests were performed at the same measuring times as in the above-described combination use test.

The hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine solution and the bunazosin solution were administered in combination or either of them alone in the same manner as in the above (1) and (2).

3. Results and Discussion

The test results are shown in FIGS. 1 and 2. IOP are shown as changes (mean±standard error) from the initial IOP.

As shown in FIG. 1, a superior ocular hypotensive effect was observed in the (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine plus bunazosin group to those in the single drug treatment groups, i.e., the (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine alone group and the bunazosin alone group. Furthermore, the action remained in the combination treatment group even after 3 or 4 hours, when the ocular hypotensive effect disappeared in the single drug treatment groups, showing improvement of the prolonged action.

Similarly in FIG. 2, a superior ocular hypotensive effect was observed in the hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine plus bunazosin group than in the single drug treatment groups, i.e., the hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine alone group and the bunazosin alone group. Furthermore, since the action remained in the combination treatment group even after 5 hours, when the ocular hypotensive effect disappeared in the single drug treatment groups, showing improvement of prolongation of the action.

The above results revealed that a potent ocular hypotensive effect and improvement of the prolonged action could be obtained by using bunazosin and (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine or hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine in combination. 

1. (canceled)
 2. A method for treating glaucoma in a subject in need thereof, comprising: administrating to said subject an effective amount of a Rho kinase inhibitor and an effective amount of an α₁ blocker, wherein the Rho kinase inhibitor is (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine or a salt thereof, or hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine or a salt thereof.
 3. The method of claim 2, wherein the effective amount of the Rho kinase inhibitor is from 0.1 to 1000 μg per day.
 4. The method of claim 3, wherein the effective amount of the α₁ blocker is from 50 to 250 μg per day.
 5. The method of claim 4, wherein the α₁ blocker comprises at least one of bunazosin and bunazosin hydrochloride.
 6. The method of claim 2, wherein a solution comprising the Rho kinase inhibitor at 0.5% is administered.
 7. The method of claim 6, wherein a solution comprising the α₁ blocker at 0.01% is administered.
 8. The method of claim 7, wherein the solution comprising the α₁ blocker is administered prior to administration of the solution comprising the Rho kinase inhibitor.
 9. The method of claim 2, wherein a composition comprising the Rho kinase inhibitor and the α₁ blocker is administered.
 10. The method of claim 9, wherein the composition is at least one of an aqueous eye drop, a nonaqueous eye drop, a suspension eye drop, an emulsion eye drop, and an eye ointment.
 11. The method of claim 9, wherein the composition further comprises at least one selected from the group consisting of a tonicity agent, a chelating agent, a stabilizer, a pH modifier, a preservative, an antioxidant, a solubilizing agent, and a thickening agent.
 12. A method for treating ocular hypertension in a subject in need thereof, comprising: administrating to said subject an effective amount of a Rho kinase inhibitor and an effective amount of an α₁ blocker, wherein the Rho kinase inhibitor is (S)-(−)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine or a salt thereof, or hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine or a salt thereof.
 13. The method of claim 12, wherein the effective amount of the Rho kinase inhibitor is from 0.1 to 1000 μg per day.
 14. The method of claim 13, wherein the effective amount of the α₁ blocker is from 50 to 250 μg per day.
 15. The method of claim 14, wherein the α₁ blocker comprises at least one of bunazosin and bunazosin hydrochloride.
 16. The method of claim 12, wherein a solution comprising the Rho kinase inhibitor at 0.5% is administered.
 17. The method of claim 16, wherein a solution comprising the α₁ blocker at 0.01% is administered.
 18. The method of claim 17, wherein the solution comprising the α₁ blocker is administered prior to administration of the solution comprising the Rho kinase inhibitor.
 19. The method of claim 12, wherein a composition comprising the Rho kinase inhibitor and the α₁ blocker is administered.
 20. The method of claim 19, wherein the composition is at least one of an aqueous eye drop, a nonaqueous eye drop, a suspension eye drop, an emulsion eye drop, and an eye ointment.
 21. The method of claim 19, wherein the composition further comprises at least one selected from the group consisting of a tonicity agent, a chelating agent, a stabilizer, a pH modifier, a preservative, an antioxidant, a solubilizing agent, and a thickening agent. 